scholarly journals Regulation of Blood Oxygen Affinity in the Australian Blackfish Gadopsis Marmoratus: II. Thermal Acclimation

1982 ◽  
Vol 99 (1) ◽  
pp. 245-254
Author(s):  
G. P. DOBSON ◽  
J. BALDWIN
Keyword(s):  
Whole Blood ◽  
Haemoglobin Concentration ◽  
Oxygen Affinity ◽  
Thermal Acclimation ◽  
Acclimation Temperature ◽  
Blood Oxygen ◽  
Molar Ratios ◽  
Oxygen Equilibrium ◽  
Nucleoside Triphosphates ◽  
Blood Oxygen Affinity

1. The effects of thermal acclimation on whole blood oxygen affinity were examined in the freshwater blackfish Gadopsis marmoratus. 2. Oxygen equilibrium curves for 20°C-acclimated fish were shifted to the right of curves obtained for 10°C-acclimated fish when determined at both 20°C and 10°C. Oxygen equilibrium curves obtained for solutions of stripped haemoglobin prepared from blood of 20°C- and 10°C-acclimated fish did not show the differences observed for whole blood. 3. Thermal acclimation did not alter the number, migration rates, or relative amounts of the five electrophoretic forms of haemoglobin present in blackfish blood. 4. The intraerythrocytic concentration of nucleoside triphosphates was higher in the 20°C-acclimated fish than in 10°C-acclimated fish, while the whole blood haemoglobin concentration was lower in the 20 °C-acclimated fish. These differences gave NTP: Hb4 molar ratios of 1.68 for the 20°C-acclimated fish and 1.32 for 10°C-acclimated fish. The effects of nucleoside triphosphates on oxygen affinity were similar for stripped haemoglobins of both acclimation groups. 5. The change in NTP:Hb4 molar ratios with acclimation temperature acts to enhance oxygen unloading to the tissues rather than oxygen uptake at the gills at the higher acclimation temperature. As the waters inhabited by the blackfish retain high oxygen tensions at 20°C, these changes in blood oxygen affinity could be considered adaptive if they were associated with elevated rates of oxygen-dependent metabolism at the higher temperatures.

Regulation of Blood Oxygen Affinity in the Australian Blackfish Gadopsis Marmoratus: I. Correlations between Oxygen-binding Properties, Habitat and Swimming Behaviour

1982 ◽  
Vol 99 (1) ◽  
pp. 223-243
Author(s):  
G. P. DOBSON ◽  
J. BALDWIN
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Swimming Behaviour ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Low Oxygen ◽  
Binding Properties ◽  
Molar Ratios ◽  
Blood Oxygen Affinity ◽  
Low Oxygen Affinity

1. The regulation of whole blood oxygen affinity in the freshwater blackfish Gadopsis marmoratus Richardson has been examined, and correlations made between oxygen-binding properties and the habitat and swimming behaviour of the fish. 2. Blackfish whole blood has a low oxygen affinity relative to other fish bloods reported in the literature. This is not due to a low oxygen affinity of the stripped haemoglobins, but arises from interactions between haemoglobin and intraerythrocytic modulators. 3. The presence of high concentrations of ATP, and to a lesser extent GTP, in the erythrocyte, together with the effect of these nucleoside triphosphates on the oxygen affinity of haemoglobin solutions at physiological NTP: Hb4 molar ratios, demonstrates that this class of compounds is a major regulator of oxygen affinity in blackfish blood. 4. The oxygen affinities of whole blood and haemoglobin solutions are sensitive to pH, with haemoglobin solutions displaying a relatively large alkaline Bohr coefficient of - 1.05 over the physiologically relevant pH range of 6.5–7.0. 5. Although increasing Pco2, lowers the oxygen affinity of whole blood, it does so only through the effect on pH, as pH-buffered haemoglobin solutions show no oxygen-linked CO2 binding. This lack of oxygen-linked CO2 binding has not been reported for any other naturally occurring vertebrate haemoglobins. 6. Muscle morphology and biochemistry, and behavioural observations, indicate that the blackfish uses anaerobic energy metabolism during rapid swimming and in recovery. 7. It is concluded that the oxygen-binding properties of blackfish blood reflect adaptations for maintaining adequate tissue oxygenation for animals at rest and during slow sustained swimming in waters of high oxygen tensions.

scholarly journals Oxygen Affinity in Hemoglobin Köln Disease

Blood ◽  
1972 ◽  
Vol 39 (3) ◽  
pp. 398-406 ◽  
Author(s):  
Frank G. de Furia ◽  
Denis R. Miller
Keyword(s):  
Whole Blood ◽  
Normal Values ◽  
Cell Mass ◽  
Oxygen Affinity ◽  
Red Cell ◽  
Blood Oxygen ◽  
Red Cell Mass ◽  
High Oxygen Affinity ◽  
Blood Oxygen Affinity

Abstract Oxygen affinity studies in a splenectomized patient with sporadically occurring Hb Köln disease revealed high whole blood oxygen affinity (P50 O2 17.6 mm Hg) with increased 2, 3-diphosphoglycerate (DPG), low ATP, and normal RBC ΔpH. Isolated electrophoretically slow migrating Hb Köln had a high oxygen affinity, decreased Hill’s number, and normal DPG reactivity. Functional evidence for hybrid tetramers with normal mobility is presented. Partial deoxygenation may play a role in the denaturation of the Hb Köln molecule and thus account for a higher oxygen affinity (low P50 O2), measured by the mixing technique, than the actual values for P50 that exist in vivo. Increased oxygen affinity and decreased P50 O2 would result in increased erythropoiesis and account for a well-compensated hemolytic process in this patient with a normal red cell mass and normal values of hemoglobin.

Effect of Metrizamide on Whole Blood Oxygen Affinity

1978 ◽  
Vol 19 (4) ◽  
pp. 688-692 ◽  
Author(s):  
S. Berglund ◽  
T. Almén ◽  
B. W. Johansson
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Blood Oxygen ◽  
Blood Oxygen Affinity

scholarly journals Oxygenational properties and phosphorylated metabolic intermediates in blood and erythrocytes of the dogfish, Squalus acanthias

1983 ◽  
Vol 103 (1) ◽  
pp. 95-108
Author(s):  
R. M. Wells ◽  
R. E. Weber
Keyword(s):  
Thin Layer ◽  
Whole Blood ◽  
Oxygen Affinity ◽  
Squalus Acanthias ◽  
Blood Oxygen ◽  
Equilibrium Curve ◽  
Metabolic Intermediates ◽  
Blood Oxygen Affinity ◽  
Layer Chromatography ◽  
Haldane Effect

A typical whole blood O2-equilibrium curve from Squalus acanthias had a P50 of 13.2 mmHg and was slightly sigmoidal, having an n value of 1.6 at 15 degrees C, PCO2 = 2.2 mmHg (pH = 7.85). A small Bohr effect was present (phi = −0.28) together with a weak Haldane effect and no Root shift. The predominant trinucleotide, determined by thin layer chromatography, was ATP (0.44 +/− 0.13 S.D. mmol 1(−1) blood) with smaller amounts of GTP present (0.07 +/− 0.02) S.D. mmol 1(−1). Total nucleotide concentrations, determined enzymatically, were low by comparison with teleosts. Incubation of erythrocytes with or without oxygen, or in the presence of a metabolite-enriched ‘cocktail’ showed limited potential for phosphate cofactor regulation of blood oxygen affinity.

scholarly journals ALLOSTERIC CONTROL OF OXYGEN BINDING BY HAEMOGLOBIN DURING EMBRYONIC DEVELOPMENT IN THE CROCODILE CROCODYLUS POROSUS: THE ROLE OF RED CELL ORGANIC PHOSPHATES AND CARBON DIOXIDE

1993 ◽  
Vol 175 (1) ◽  
pp. 15-32 ◽  
Author(s):  
G. C. Grigg ◽  
R. M. G. Wells ◽  
L. A. Beard
Keyword(s):  
Embryonic Development ◽  
Whole Blood ◽  
Marked Effect ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Embryonic Life ◽  
Crocodylus Porosus ◽  
Blood Oxygen Affinity ◽  
2,3 Dpg

The P50 of whole blood [30°C, PCO2=2.08 kPa (15.6 mmHg)] decreases during embryonic development from approximately 6.7 kPa (50 mmHg) at 15 days to about half this value at hatching (86 days), paralleling a decrease in ATP from 100 to 5–10 micromole g-1 Hb. There is also a progressive changeover from embryonic to adult haemoglobin (HbA). A pulse of 2,3- diphosphoglycerate (2,3-DPG) (18 micromole g-1 Hb) occurs late in embryonic life. It has no effect on whole-blood oxygen-affinity and falls rapidly at hatching to values typical of post-hatchling crocodilians in general (<1.0 micromole g-1 Hb). ATP has a marked effect on the oxygen affinity of embryonic haemoglobin (HbE) but not on HbA. 2,3-DPG has only very small effects on the oxygen affinities of HbE and HbA. CO2 has a small effect on the oxygen affinity of HbE but a marked effect on that of HbA. Values of PO2 measured in the chorio-allantoic artery [2.9 kPa (22 mmHg)] and vein [5.9 kPa (52 mmHg)] imply an increase in saturation from approximately 30 % to more than 80 %. Neither whole-blood oxygen-affinity nor ATP level was altered in response to an experimental 7-day exposure to low ambient oxygen levels [10.7 kPa (80 mmHg)]. The results do not lend themselves easily to the pan-selectionist paradigm in which all physiological traits are viewed as being adaptive.

scholarly journals Antarctic Fish Blood: Respiratory Properties and the Effects Of Thermal Acclimation

1984 ◽  
Vol 109 (1) ◽  
pp. 265-279
Author(s):  
VILHELM TETENS ◽  
RUFUS M. G. WELLS ◽  
ARTHUR L. DEVRIES
Keyword(s):  
Oxygen Affinity ◽  
Antarctic Fish ◽  
Thermal Acclimation ◽  
Temperate Species ◽  
Molar Ratio ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Low Oxygen ◽  
Blood Oxygen Affinity

1. The effects of thermal acclimation on whole blood oxygen affinity were examined in the antarctic fish Pagothenia borchgrevinki. 2. 4.5°C-acclimated fish had a P50 value of 26.7 mmHg at pH 8.1, compared to 20.7 mmHg for −1.5°C-acclimated fish. The apparent heat of oxygenation, ΔH = −26.7 kJ mol−1, is comparable to values for temperate species. 3. Warm-acclimation was followed by an increased ATP: Hb4 molar ratio, resulting in an augmentation of the thermal effect on oxy-haemoglobin affinity. This may be considered adaptive in a constantly well oxygenated environment, where oxygen loading at the gills is secured. Unloading to the tissues is thereby enhanced, supporting an elevated rate of aerobic metabolism at higher temperatures. 4. In vivo blood pH was high, between 8.10 and 8.25 at −1.5°C. Astrup titration revealed arterial CO2 tensions of less than 0.8 mmHg, indicating relative hyperventilation and low oxygen extraction efficiency in antarctic fish. 5. Blood oxygen affinities of four antarctic nototheniid species were low (P50 between 11.9 and 20.7 mmHg at pH 8.1 and --1.5°C) in comparison with the temperate species Notothenia angustata (P50 = 10.8 mmHg). The zoarcid Rhigophila dearborni had a high blood oxygen affinity (P50 = 4.3 mmHg). Blood oxygen-binding properties are discussed in relation to the polar environment, mode of life, and the concept of cold adaptation.

Sign in / Sign up

Export Citation Format

Share Document